DDR4 CL14 vs CL15 vs CL16, Any major difference?

[gigabyte06]

Looking for 16gb ( 2x8) of DDR4 and I'm trying to figure out what speed to get for the Z270 motherboard. My MB Supports DDR4 3866+(OC)
PC will be only used for gaming.

I'm looking at.....
G.Skill 3200 16-16-16-36
G.Skill 3000 15-16-16-35
G.Skill 3200 14-14-14-34

Not sure if there is some sort of guide that tells what a speed can be Overclocked to or not. Suggestions what I should get is appreciated.

 

[fourseven]

it mean the latency from its ram.
the lower the better, overall performance is not big different.
for gamming dual channel 2x8 16gb with 3200 MHz speed (XMP) is enough.
I suggest take G-skill Trident-Z if you want to take "G-skill" brand.